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' N. H. RAYMOND. I METHOD OF CLEANING PlPES. APPLICATION FILED DEC-5.1911.

L1 9%,5&8, v Patented Aug 15, 1916.

in van-72" ama? i maaaaa v OF BFUEIEO, NEW YORK ASSIGNOR. 1'0 OLIlETON 1H1 urac- MASSACHUSETTS, A CORPORATION OF NEW g ranrnon or 'otnaumorrrns.

To aZZ'wkmr att ma 05mm.- a Be it known that l, NnLsoN -RAYMOND,

i a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have. invented new and. useful Improvements in 'Methods .of; Cleaning Pipes, of which the followingis a specification. i

This invention relates to a method for cleaning metallic pipes. or tubes which are more particularly designed for use as elec-' trical conduits. V

In the manufacture of such pipes and particularly those made from iron, more or less scale, grease and other deleterious matter adheres to the inner and outer surfaces of the same and it therefore becomes necessary to clean these pipes before applying thereto a protective coating by galvamzlng or enameling. .Heretofore the scale, grease and other deleterious material has been removed from the pipes preparatory to applying the protecting coating thereto by immersing the pipes in a ickling solution consisting, for instance, 0 a mixture of sulfuric and hydrochloric acid. Owing to the fact that the scale is usually thicker on the inner side of the-pipe than on the outer side and for the further reason, that the 7' innerside ofthe pipe usually contains more or less s 1l1ca scale while the outer side is comparatively free from silicascale and instead thereof has a light mill scale, an acid treatment of the pi es as heretofore practised is objectionab e because the outer side of the pipes is acted upon excessively by the time the abid has removed the scale, grease and dirt on the inner side of the. pipe. This results in pitting the exterior of the pipes so that they look bad and cannot be covered umformly with enamel or other protective coating. Furthermore, when the pipe has been previously threaded on its exterlor this.

1 soda,

speciflcafion of Letters Patent. Pamqgymhedl A 15 1 9mg hppli cation flleu D ecember't, 1911.

Serial No. $6t,076.'

In practising my invention a cutting or cleaning solution consisting, for instance, of

means the solution is maintained in a thoroughly mixed condition, any bubbles.

formed on the interior of the pipe are bursted,.and new solution is constantly supplied, sothat all parts of the internally grease and scale coated surface of the pi e are attacked by the solution and thorough y cleaned. After the pipe has been thus cleaned on its interior a neutralizin solution is propelled through the same or the purpose of killing the traces of acid which are deposited on the interior of the pipe and arresting the cutting action of the same. This neutralizing solution may contain lime, lye or any other alkali or caustic and the same is also preferably circulated through the pipe by taking the solution which escapes from one end of the pipe and reintroducing the same at the other end of the pipe. After the effect of the acid treatment on the interior of the pipe has been thus neutralized this surface of the pipe is washed outiso as to remove therefrom the traces of cutting and neutralizing solutions, this being preferably effected by circulating water through the pipe in the same manner in which the cleaning or'cutting and the neutralizing solutions were. circulated through the pipe. The outer side of the pipe may be cleaned in any suitable way, for instance, by passing the same through a pair of scratch rolls Which "mechanically remove the dirt and scale adheringthereto and the same may also be cleaned chemically by immersing the same for a suitable period in an acid cleaning solution at which time this solution may also enter the interior of the pipe and further clean the bore of the'same. Any-traces of acid adhering to the inner and outer side of the pipe may be neutralized by immersing the same in a caustic solution andthen immersing the same. in water. After the pipe has been thus cleaned on its interior and exterior surfaces the same may be provided with, a protective coating. both internally and externally in any suitable manner, for instance by, immersmg the same in a bath of the desired kind protective coatstructed as follows:

1- represents an uprightwmanifold or distributing chamber which is provided on one I of its upright walls with a plurality of laterally projecting discharge nozzles 2. This distributing'chamber may be supplied at different times either with a cutting medium or solution such as sulfuric and hydrochloric acid, a neutralizing medium orsolution such as lye, and awashing medium such as water. As shown in the drawings,

the cutting solution is contained in a tank or reservoir 3 from which it is supplied to theupper part of the distributing chamber by means of a nine 1 containing a valve 5 whereby the delivery of the cutting solution to the distributing chamber may be con-- trolled. A similar tank or reservoir 6 adapted to contain a quantity of neutral zing solution is also connected with the upper end ofa distributing chamber by means\of a pipe 7 containing a valve 8 whereby the supply of neutralizing solution from the tank or reservoir 6 to the distributing chamber may be controlled.

Near its upper end the washing medium or liquid may be supplied to the tank by means of a pipe 9 containing a valve 10 whereby the supply of washing medium may be controlled. 1 4

' Each of the delivery nozzles of the distributing chamber is inserted into the front or receiving end of one of the pipes or tubes 11 which are to be cleaned, these pipes being preferably supported in a position in which they incline from their receiving toward their delivery ends by resting the same on a rack 12, as shown in the drawings, or by any other suitable means. Adjacent to the outlet ends of the pipes to be cleaned is arranged a receiving pan or catch basin 13 which is provided in its upper part with a screen 14.

15 represents a pump of any suitable construction which has its inlet connected by a pipe 16 with the lower part of the catchpan or basin while its outlet end is connected with a main return pipe 17. The latter is provided with two branch pipes 18, 19 leading respectively to the upper ends of the cutting solution tank and the neutralizing solution tank, these branch pipes being provided, respectively, withvalves 20, 21 for the purpose of controlling communication between these tanks and-the return pipe of the pump. The return pipe of the pump is also provided with a branch pipe 22 which nozzles of the distributing chamber and the valves 8, 10, 21,123 are closed, while the valves 5 and 20 are opened, thereby cutting off the supply of wash water and the neutralizing solutionand also closing the waste outlet of the pump but placing the cutting solution tank in communication-with the distributing chamber. In this position of the valves the cutting solution flows from the cutting tank into the distributing chamber and from the latter outwardly through the several discharge nozzles and into the front ends of theseveral pipes. The cutting solution then flows solely by gravity through the several ipes from the inlet to the outlet ends thereo and during this passage the cutting solution removes scale, grease and other deleterious material from the interior of the pipes. As the cutting solution escapes from the rear or tail ends of the several pipes, it drops into the catch basin or pan, any solid impurities contained therein being separated therefrom b means of the screen while theclear liquid gathers in the lower part of the pan. While the cutting solution isv thus flowing through the pipes under treatment and escapes into the catch basin the pump is in operation and carries the cutting solution from the lower part of the catch basin back into thecutting solution reservoir or tank from whence it flows again into the distributing chamber and through the pipe under treatment as before described. In this manner the cutting solution is constantly kept in circulation through the pipes to be cleaned, whereby any bubbles formed on the pipes are broken, the solution is constantly agitated, and new or active parts of this solution having a cutting capacity are brought into contact with all parts of the interior of ,the pipes and a thorough cleaning of the pipes is insured. After this cutting solution has been circulated in this manner a sufficient length of time to thoroughly clean the pipes, which time may be determined from experience and also by noting the condition of the pipes preparatory to cleaning the same, the cutting solutiontank is cut off by closing the valves 5 and 20, it being understood that all of the cutting solution is first returned to the tank 3, by means of the pump before the valve 20 opened and the solution of this tank is permitted to flow into the distributing chamber,

memes distributing chamber and again circulated through the pipes under treatment as long as necessary to thoroughly neutralizeall traces of the acid which are left in the pipes after the cutting treatment. After'this neutralizing treatment the valve 8 is closed so as to cut oil the further supply of neutralizing solution to the distributing chamber and after the pump has returned to the neutralizing tank all the neutralizing solution in the distributing tank or chamber, tubes 11 and catch basin, then the valve 21 of this tank is also closed. The valve of the vvater supply pipe 10 and the valve 23 of the Waste pipe are now opened, thereby causing Water to flow into the distributing chamber and through the several pipes under treatment and into the catch basin, from which latter the Water is taken by the pump and discharged through the Waste pipe 22 to a sewer or other receptacle provided for this purpose.

My improved process for cleaning pipes permits this operation to be efl'ected economically and expeditiously and leaves the pipes in a condition in' which they are free from pits or similar defects, and enables the same to be enameled uniformly and present a finished and even appearance.

I claim as my invention:

1. The herein described method of cleaning tubes which comprises passing a cutting solution through the tube, and then passing a neutralizing) solution through the tube, said solutions eing returned from the outlet to the inlet of said tube.

- 2. The herein described method of cleanber,1911 L l NELSON H. RAYMOND.

Witnessesw 'lnno. L. Porr, ANNA HEIGIs.

to ing tubes which comprises passing a cutting 

